It really depends on the purpose. I cannot tell anything about chances of getting hired as a Perl programmer. Being paid to administer and develop Java applications, my point of view is certainly different from a real Perl developer or someone who programs applications in another scripting language. My field of application for a scripting language is first and foremost maintenance. I need to analyse log files and I need to test applications on a semi-automated base. With some knowledge of Python and Ruby I'm quite certain that these are not suitable for my tasks.

So I'd say: If you want to learn a universal, multi-purpose, multi-paradigm scripting language (or as Larry Wall calls it, a "postmodern language"), go for Perl. OTOH, if you want to pick a language to get a job as a developer in this very language, I have to remain silent.